Meter reading systems for reading utility usage at a utility meter are well known, examples of which are disclosed in the Sears U.S. Pat. No. 4,463,354 entitled, "Apparatus for Communicating Utility Usage Related Information From a Utility Usage Location to a Portable Utility Usage Registering Device" and in the Sears U.S. Pat. No. 5,617,084 entitled "Apparatus for Communicating Utility Usage Related Information From a Utility Usage Location to a Utility Usage Registering Device" both of which are incorporated by reference herein. These utility meter reading systems and other types of utility meter reading systems utilize meter transmission units which are located at and connected to an individual utility meter at which it is desired to collect utility usage information.
Some utility meters commonly referred to as "pit set" utility meters are located in an underground pit and it is a requirement for the meter transmission units which are associated with pit set meters to be located within an opening in the pit cover with the meter transmission unit extending into the pit and supported by the pit cover.
Meter transmission units for use with pit set meters have particular requirements and problems associated with the use of the meter transmission units in an underground pit. The meter transmission units are normally supported in an opening in the cover of the pit. The pit covers are constructed of concrete, plastic or metal which can interfere with the transmission of signals from the meter transmission unit. Accordingly, it is important that the antenna from the meter transmission unit extend through the opening in the pit cover to insure reliable transmission of data from the meter transmission unit. Additionally, the bottom surface of the pit cover in many cases is irregular. Since the pit set meters are frequently located in sidewalks and streets, the covers must be sufficiently rigid to allow traffic to pass over the pit cover without damage thereto. Frequently, ribbed structures are provided on the bottom surface of the pit cover to reinforce the pit cover, further increasing the non-uniformity of the bottom surface of the pit cover which in the prior art created problems in rigidly securing the meter transmission unit within the opening in the pit cover. The meter transmission unit must extend through the top surface of the pit cover to provide for reliable data transmission and must also be impervious to traffic flow over the pit cover. This is a particular problem when snowplow blades pass over the pit cover. The meter transmission unit can not extend above the pit cover to an extent that it would be damaged by a snow plow or other vehicular traffic.
In addition, the sensor portion of the meter transmission unit is generally spaced apart from the main housing of the meter transmission unit. The sensor portion is connectable to the utility meter to sense utility usage and is connected to the main housing of the meter transmission by a plurality of conductors. It is desirable to permanently connect the conductors between the main housing and sensor when manufacturing the meter transmission unit to insure proper sealing where the conductors pass into the main housing and into the sensor housing. It has been found to be problematical when the sensor unit was connected to the main housing in the field due to unreliable connectors and unreliable seals and the harsh wet environment to which such seals and connectors were subjected.
The present invention overcomes the disadvantage associated with the prior art pit set meter transmission units by providing an economical meter transmission unit for use with a pit set utility meter which is readily secured through an opening disposed in the pit cover, which is readily adjustable to tightly fit the meter transmission unit within the opening in the pit cover when the pit cover has an irregular bottom surface and wherein the sensor portion of the meter transmission unit is permanently connected to the main housing of the meter transmission unit. In addition, the meter transmission unit is constructed in a fashion which reduces shipping costs by allowing the meter transmission unit to be partially disassembled for shipping. Additionally, the meter transmission unit is impervious to traffic such as snowplows and snowplow blades passing over the surface of the meter transmission unit.